Water Sports Device

ABSTRACT

A water sports device is provided which is configured for self-stabilization. The water sports device includes an active stabilization means, in the case of which the control unit provides control signals for actuators of the water sports device, actuators being active adjusting means. These can be a motor of the propulsion apparatus, adjustable flaps or nozzles, or adjustable fins, rudders, hydrofoils or individual adjustable sections thereof. Input data such as data about the position of the water sports device, power output of the propulsion apparatus, speed, acceleration and/or user inputs are evaluated in the control unit, and control commands for an actuator or a plurality of actuators are generated.

CROSS REFERENCE

This application claims priority to PCT Application No. PCT/EP2020/080695, filed Nov. 2, 2020, which itself claims priority to German Patent Application No. 10 2019 129572.6, filed Nov. 1, 2019, the entirety of both of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a water sports device, in particular a foil board, with a float, preferably in the form of a swimming board, and with a propulsion apparatus which is provided for the propulsion of the water sports device.

A water sports unit of this type is configured as a foil board, in particular, when the float is configured as a swimming board and it has at least one hydrofoil apparatus with at least one hydrofoil, in particular with at least two hydrofoils. Water sports devices of this type as a rule serve for the movement over bodies of water of persons who, to this end, stand on that side of the float which faces away from the hydrofoil apparatus. During the movement, the hydrofoil apparatus is as a rule arranged below the water surface.

BACKGROUND OF THE INVENTION

US 2018/0072383 A1 has disclosed a hydrofoil apparatus which requires a sufficiently deep body of water as a result of the foil which is used, since the hydrofoil apparatus otherwise makes contact with the bottom and is either damaged or folded away. For the use, therefore, areas of a body of water which are away from a bank or beach are as a rule necessary.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to make it possible for a water sports unit of this type to be used more simply and/or to be learned more simply.

The object according to the invention is achieved by virtue of the fact that the water sports device and, in particular, the propulsion apparatus are configured for automatic self-stabilization of the water sports device, and the water sports device has a control unit which is provided to this end.

The water sports device is comparatively unstable in a position which is spaced apart from the water surface, in particular in the case of acceleration operations and/or when cornering is carried out. In the case of conventional water sports devices in accordance with the preamble, the water sports device is controlled by way of displacement of the body weight of the user and/or, in the case of an external actuation of the water sports device, a displacement of the body weight of the user has to take place, in order to remain on the water sports device and to prevent overturning of the water sports device.

Here, a water sports device which is configured for self-stabilization can assist a user of a water sports device of this type and/or can facilitate learning of the use of a corresponding water sports device if great assistance is initially brought about and this assistance is gradually reduced. To this end, the water sports device according to the invention has an active stabilization means, in the case of which the control unit provides control signals for actuators of the water sports device, actuators being active adjusting means. These can be a motor of the propulsion apparatus, adjustable flaps or nozzles, or adjustable fins, rudders, hydrofoils or individual adjustable sections thereof. Input data such as data about the position of the water sports device, power output of the propulsion apparatus, speed, acceleration and/or user inputs are evaluated in the control unit, and control commands for an actuator or a plurality of actuators are generated.

Self-stabilization of the water sports device takes place when the control commands which are generated by way of the control unit bring about a movement of the water sports device into a stable position. In the stable position, the user of the water sports device can use the latter, without running the risk of falling from the water sports device. Even a self-stabilizing water sports device can, however, capsize, sink or the user can fall from it if the transition into an unstable state takes place too rapidly or the possibilities of the water sports device for self-stabilization are exceeded. This is the case, for instance, if the necessary adjustment of an actuator is greater than the available adjusting range.

The stable position of the water sports device can be a stable equilibrium position of the system which is not stabilized actively and consists of the water sports device and the user. In this case, active stabilization has to take place only if the limit for returning into the stable equilibrium has been exceeded. It can also be, however, an unstable equilibrium position of the system which is not stabilized actively or an equilibrium position of the system which is stabilized actively. In these two cases, a permanent intervention of the control device is necessary, in order to keep the system consisting of the water sports device and the user in the stable position. The system can also have more than one stable position. The water sports device is therefore stabilized actively by way of actuator adjustment of adjusting elements and/or influencing of signals which determine the propulsion.

The float is, in particular, a flat, elongate body, the density of which lies considerably below that of water. The float is configured, in particular, in such a way that, during operation, it is preferably arranged at any rate partially above the water surface independently of a movement speed. During operation, the holding apparatus reaches from the float to the hydrofoil apparatus below the float. A buoyancy force which is generated by way of the hydrofoil apparatus is transmitted by way of the holding apparatus to the float.

The hydrofoil apparatus is preferably provided, at least in the operating position, with at least one hydrofoil which is of flat and preferably at least partially wing-shaped or fin-shaped configuration. The width (measured transversely with respect to the movement direction) of the hydrofoil apparatus is, in particular, at most twice as great as the width of the float. The hydrofoil apparatus serves for stabilizing the movement with the water sports device and for generating a buoyancy in the process, the hydrofoil apparatus preferably having hydrofoil ends in order to boost these effects, which hydrofoil ends are angled with respect to the substantially flat water surface. In order to boost these effects, furthermore, the water sports device has, in particular, a plurality of hydrofoils which are spaced apart from one another in the movement direction and/or are spaced apart from the float to different extents. The hydrofoil apparatus therefore comprises at least one hydrofoil and its holder and possibly a propulsion apparatus.

The at least one link is configured, in particular, as a rigid strut. In particular, the link is mounted pivotably relative to the float and/or relative to the hydrofoil apparatus. As an alternative or in addition, the at least one, first link is mounted such that it can be moved, in particular can be displaced, translationally relative to the float and/or relative to the hydrofoil apparatus. The hydrofoil apparatus is coupled to the first link, in particular, indirectly, via further components such as for example the link, or directly. In general, for example, a linkage component which is attached movably and, in particular, in an articulated manner, but is otherwise rigid and is configured as a solid body or so as to be hollow is called a link, via which parts of the water sports device can be moved relative to one another, possibly in combination with one or more further links. The holding apparatus preferably has links which can be pivoted with respect to one another and/or can be displaced into or on one another and are therefore, for example, telescopic.

The automatic self-stabilization preferably takes place by way of the propulsion apparatus which is configured for, in particular, automatic thrust control, furthermore, in particular, for automatic thrust vector control. In the case of thrust control, the thrust of the propulsion apparatus can be adapted to the current stability state of the water sports device. In the case of automatic thrust control, the adaptation of the thrust takes place automatically by way of control commands which are determined in the control unit. Said control commands are generated on the basis of sensor data. If the water sports device is therefore intended to move more rapidly, but the user starts to lean back in the process and, as a result, the water sports device threatens to become unstable, the propulsion apparatus will automatically reduce the thrust. In the case of a braking operation, a thrust reduction can likewise automatically be stopped or reversed if the user has shifted his/her weight too far forward and instability or turning over of the water sports device is threatened. Conversely, an increased thrust can also likewise compensate for a weight shift toward the front, and vice versa. Thrust vector control is particularly advantageous. Here, not only the magnitude of the thrust but also the direction, in which the thrust takes place, can be influenced. As a result, for example, instabilities as a result of external forces such as, for example, wave or wind forces which act from the side can be compensated for. The additional degree of freedom of the automatic thrust vector control therefore makes more sensitive self-stabilization of the water sports device possible.

The propulsion apparatus particularly preferably has a vector nozzle. The vector nozzle is arranged in such a way that the drive jet of accelerated liquid which is generated by way of the propulsion apparatus flows through said vector nozzle. It is preferably arranged at the rear end of the propulsion apparatus. By way of a vector nozzle of this type, the direction, in which the drive jet points, can preferably be oriented freely within a cone which adjoins the end of the propulsion apparatus. Within this cone, the direction of the drive jet can be set freely, and stabilization of the water sports device can therefore be achieved.

The control unit is preferably configured for preferably multiple-axis stabilization of the float during the transition into the operating position and/or in the operating position. Stabilization of this type can therefore compensate for both dipping in the movement direction toward the front or toward the rear, for example as a consequence of weight shifts of the user or insufficient weight shifting of the user, and movements about the longitudinal axis which can occur, for example, when cornering or else in the case of careless shifts of the body weight of the user or in the case of shifting of the body weight of the user which has not taken place but is necessary. In particular, these disruptions of the stable state can be addressed at the same time.

As an alternative or in addition to a vector nozzle, the propulsion apparatus has a pivotable propeller. Said propeller which can preferably be pivoted about two spatial axes makes it possible, in a similar manner to the vector nozzle, to set the direction, in which a drive force acts. As a result, the self-stabilization of the water sports device according to the invention can be achieved or assisted.

The propulsion apparatus preferably has at least one pivotable guide vane. Here, the guide vane is preferably arranged at the end of the propulsion apparatus behind the propeller and/or impeller. The drive jet, generated by the propeller or impeller, of the propulsion apparatus can be oriented by way of the guide vane. At least two pivotable guide vanes are preferably provided which are arranged at a 90° angle with respect to one another and preferably penetrate one another, in order to obtain a controllability in at least two spatial directions. At least four guide vanes are particularly preferably provided which are arranged in a cross shape, the arms of the cross which are situated next to one another forming in each case 90° angles. If the guide vanes which are arranged in a cross can be moved in each case individually, control can take place about a longitudinal axis or roll axis which runs through the propulsion apparatus, which makes a controllability about three spatial axes possible. This can contribute to the stabilization of the water sports unit when cornering, in particular.

The propulsion apparatus preferably has a plurality of nozzles which point in different directions. Here, said nozzles can either be movable per se or can be arranged rigidly. A drive jet which is generated by way of a propeller or preferably by way of an impeller is ejected through the nozzles, it being possible for that proportion of the drive jet which is ejected through individual nozzles to be varied via control elements such as flaps or valves. Here, the nozzles can be arranged in such a way that, in the case of homogeneous ejection of the drive jet through all the nozzles, the result is a neutral propulsion force which is directed forward. In the case of a variation in the propulsion jet which is ejected through the individual nozzles, forces and/or torques can therefore be applied to the water sports device in certain directions, which forces and/or torques can be used for stabilizing the water sports device.

The water sports device preferably has at least one sensor, preferably a plurality of sensors, from a group comprising gyro sensors, speed sensors, position sensors for systems such as GPS, Galileo, Beidou and/or Glonass, distance sensors, for example in the form of echo sounders or sonar sensors, infrared sensors and inclinometers. The position of the water sports device relative to a point of comparison or a state or positional change can be determined by way of at least one of said sensors. The signals of the at least one sensor are particularly preferably processed in the control unit, and control signals are configured by the control unit on the basis of said signals. In this way, the control unit can derive the measures necessary for correction of the position or the positional change on the basis of the signals, and can output corresponding control signals, in order to bring about automatic self-stabilization.

A plurality of selectable movement profiles are preferably stored in the control unit. The stored movement profiles can differ, for example, in terms of the extent and/or the time of an intervention of the automatic self-stabilization. For instance, a movement profile which is created for beginners can already intervene to a pronounced extent in the case of small deviations, whereas the automatic self-stabilization for an experienced user can be switched off completely. Furthermore, profiles are conceivable, in which initially merely short and light corrections take place, in order to indicate the requirement for a correction to the user, or profiles, in which the corrections which are necessary for stabilization are delayed as far as possible, and a maximum possible correction is initiated only when it is just still possible for automatic self-stabilization to take place by way of this. The stored movement profiles can be selected in a manner which is dependent on the requests or the ability of a user, and in each case make different movement experiences possible.

The control unit is preferably configured for setting different spacings from the water surface in the operating position. Said spacings can be selected, for example, in a manner which is dependent on the experience of the user. In the case of beginners, the spacing can be kept low, whereas experienced users can use the water sports device at a great spacing from the water surface. Furthermore, the spacing can be varied in a manner which is dependent on the position or the location of the water sports device or in a manner which is dependent on the movement situation. The spacing can thus be decreased when cornering, in order to improve the stability of the water sports device. The spacing can also be increased when cornering, however, in order to prevent the float from coming into contact with the water surface in the case of pronounced leaning positions of the water sports device. The spacing can likewise be increased when moving over a shallow location, in order to avoid damage to the holding apparatus, hydrofoil apparatus and/or propulsion apparatus. In shallow bodies of water, the spacing from the water surface can also be decreased just as far as possible, however, in order to decrease the risk of injury to the user of the water sports device in the case of a fall from the water sports device.

The hydrofoil apparatus is preferably configured for setting different angles of attack at least parts of the at least one, preferably at least two hydrofoils and/or of at least one rudder. Here, the rudder can be configured as an adjustable section of a hydrofoil or as a separate component of the hydrofoil apparatus. As a result, as an alternative or in addition, stabilization of the water sports device can take place. By way of the adaptation of the angle of attack, the buoyancy which is generated by way of the hydrofoils can be adapted in terms of the direction and/or the magnitude. Via this, stabilization and/or control of the water sports device can take place. The angle of attack and therefore the buoyancy can be reduced at high speeds of the water sports device, in order that the float is not raised excessively above the water surface. At the same time, as a result, the drag can be decreased and the speed can be increased. Conversely, the angle of attack can be increased at low speeds, in order to increase the buoyancy. By way of different angles of attack of two hydrofoils which lie opposite one another, a movement about an axis which extends in the movement direction can be brought about or an undesired movement out of an equilibrium position can be corrected and the water sports device can therefore be stabilized. Cornering can be assisted or else initiated. By way of different angles of attack of two hydrofoils which are arranged behind one another, pitching of the watercraft as a result of waves, for example, or as a result of a weight shift of the user on the watercraft toward the front or toward the rear can be countered. Overall, automatic self-stabilization of the watercraft can thus be achieved on its own or in conjunction with other measures.

The control unit is assigned at least one handheld unit which has, in particular, a thumb control means. As a result, the speed of the water sports device can be set, for example, by way of the user or else a third party. Here, a thumb control means means that the water sports device can be controlled via movements of the thumb relative to the handheld unit. The handheld unit preferably has an operating element which can be moved in two directions and from which control signals in two directions which are linked, in particular, to the speed of the water sports device and cornering of the water sports device can be derived. The handheld unit can also have a 2D touchpad, in the case of which movements of a finger, preferably of the thumb of the user, are converted into corresponding control signals in two directions.

The water sports device preferably has a dead man's apparatus. In conjunction with the water sports device, a dead man's apparatus ensures that the water sports device switches off automatically if the user moves away from the water sports device, in particular falls from the water sports device. To this end, a token can be provided which the user attaches to his/her clothing and which is connected by a cable or wirelessly to the water sports device. If the token is too far away from the water sports device, the latter switches off. This takes place, for example, electronically in the case of wireless tokens. In the case of a wired token, the switch-off can also take place mechanically, by a contact being interrupted as a result of pulling of the cable. The removal of the cable can also be monitored and registered electronically, however.

The hydrofoil apparatus can preferably be transferred, in particular can be retracted and extended and/or folded, via the holding apparatus out of a rest and/or starting position into an operating position below the float. In the rest and/or starting position, the hydrofoil apparatus is arranged closer to the float than in the operating position, for the benefit of increased compactness of the water sports device. In particular, the holding apparatus is folded in and/or retracted in order to transfer the hydrofoil apparatus and the rest and/or starting position. In particular, the at least one, first link is pivoted relative to the float by at least 20°, preferably by at least 40°, particularly preferably by at least 80° in order to transfer the hydrofoil apparatus. The hydrofoils are preferably spaced apart from the float by not more than 50 cm in a side view in the rest and/or starting position. The water sports device can be transported in a compact manner as a result of the transferring capability of the hydrofoil apparatus via the holding apparatus. This is particularly advantageous, however, in one refinement, in which the hydrofoil apparatus is arranged directly below the float, preferably at least partially within the float, in the rest and/or starting position, can already be mounted by a user in a flat bank section, and the water sports device can be moved into deeper water, where the hydrofoil apparatus is then transferred into the operating position. A water sports device of this type can also be used up to flat sections of a body of water close to the bank toward the end of use after transfer of the holding apparatus into the rest and/or starting position from an operating position. A water sports device of this type is particularly user-friendly.

The holding apparatus and, in particular, the holding apparatus preferably have a drive which is provided with an energy store, via which drive the hydrofoil apparatus can be transferred out of a rest and/or starting position into the operating position and/or out of the operating position into the rest and/or starting position. In particular, the hydrofoil apparatus can be retracted and/or extended and/or folded in and/or out, here. The water sports device can therefore be mounted and started close to the beach or bank, the hydrofoil arrangement being situated in a rest and/or starting position. In the case of a sufficiently deep bottom, the hydrofoil arrangement is then transferred into the operating position. In the case of returning to the starting point, the hydrofoil arrangement is then transferred into the rest and/or start position close to the float again when the spacing from the bottom becomes smaller. The person situated on the float can move back considerably closer to the bank or the beach without jeopardizing the integrity of the water sports device. The transition into the rest and/or starting position can also take place with intermediate positions being taken up, in which the hydrofoil arrangement is not yet as close to the float as in the rest and/or starting position. In order to trigger the actuation, the drive is provided with a control unit which receives a signal triggered by a utilizing person and sends a control signal to the drive.

The energy storage is configured, in particular, for storing energy which is necessary for a transfer of the hydrofoil apparatus. The store preferably has a rechargeable battery for storing electric energy, a tank for storing a pressurized fluid, or a mechanical energy store such as a spring. The drive is correspondingly preferably configured as an electro-mechanical or electro-pneumatic drive. In a first embodiment of the invention, the energy store is configured for feeding a motor which initiates the transfer of the hydrofoil apparatus. In one preferred further refinement of the invention, the energy store releases stored energy directly, without a motor being connected in between, as mechanical or kinetic energy for the transfer. The energy store is preferably coupled mechanically on one side to the holding apparatus, and is coupled on the other side to a charging device such as a motor which is configured for charging the energy store, in particular during the use of the water sports device.

As a result of the water sports device according to the invention, the physical effort to be expended by the user for the transfer of the hydrofoil apparatus can be reduced considerably. Rather, the drive is merely to be triggered for the transfer, which drive independently implements the transfer or at least reduces the manual effort.

The holding apparatus preferably has at least one further link which is mounted pivotably at one end on or in the float and is arranged pivotably at the other end on the hydrofoil apparatus. In particular, the first link and the further link are arranged behind one another in the movement direction at least in the operating position of the hydrofoil apparatus. In particular, therefore, at least one of the links is arranged in a pivotably movable manner on a receptacle for the at least one hydrofoil apparatus or a receptacle of the hydrofoil apparatus. Here, the pivot axes are oriented, in particular, transversely with respect to the movement direction and parallel to the water surface during operation. As a result, the holding apparatus can be configured as a parallelogram guide which is particularly reliable and by way of which the hydrofoil apparatus also remains, in particular, below the float in the rest and/or starting position.

As an alternative or in addition, the holding apparatus preferably comprises further links which are coupled in each case to one of the two links and adjoin one another at least in the operating position between the float and the hydrofoil apparatus and transmit force to one another. In particular, the two first or further links are pivotably movable with respect to one another, as a result of which a toggle lever or folding mechanism can be produced as holding apparatus. For example, in each case two links which form an elbow joint are arranged behind one another in the movement direction.

As an alternative or in addition, at least one of the two links is displaceable at least at one end relative to the float or relative to the hydrofoil apparatus. As a result, a scissor mechanism for the transfer of the hydrofoil apparatus can be configured. As an alternative or in addition, at least one of the links is mounted such that it can be moved pivotably relative to the float and/or relative to the hydrofoil apparatus about a pivot axis which runs parallel to the movement direction. In particular, the holding apparatus comprises a total of at least four links which are coupled to one another in the manner of a scissor jack (the links which lie in each case opposite one another are at any rate arranged in parallel). Transfer mechanisms and therefore water sports devices which can be handled particularly reliably can be provided by way of the above-described mechanical features of the holding apparatus and/or the links.

As an alternative or in addition, the hydrofoil apparatus has telescopic links which are mounted such that they can be displaced longitudinally into or on one another and via which the spacing of the hydrofoil apparatus from the float can be varied.

In one advantageous refinement of the invention, the water sports device has at least one depth and/or proximity sensor which is connected to a control apparatus which is configured to control the drive. The control apparatus can also be part of the control device, that is to say can be configured by way of the latter, it being possible for the control unit to be of modular construction and/or to be arranged distributed spatially in the water sports device. Thus, for example, that part of the control unit which represents the control apparatus of the drive can be arranged spatially in the vicinity of the drive, while that part of the control unit which acts on the propulsion apparatus can be arranged at another position in the water sports device.

The sensor is configured, in particular, for measuring and immersion depth of the water sports device or of a constituent part of the latter, and/or for measuring a spacing of the water sports device from the bottom (of the body of water). As an alternative or in addition, the sensor or one of the sensors is configured for measuring a spacing of the water sports device from an obstacle, in particular from any further water sports devices, preferably in the movement direction. The drive is configured, in particular, in such a way that the spacing of the hydrofoil apparatus from the float is preferably varied during movement in a manner which is dependent on the sensor data, in particular during the propulsion of the water sports unit; in particular, the hydrofoil apparatus is transferred at least partially. As a result, damage to the water sports device as a result of contact with the bottom can be avoided, in particular close to the beach or bank, and unintended operating situations such as, for instance, as a result of the float which is spaced apart too far from the surface of the body of water can be avoided, and the user is assisted in the operation of the water sports device. Therefore, the hydrofoil apparatus is preferably extended automatically and/or after release by way of the utilizing person, in an automatic manner after starting close to the bank or beach, if there is sufficient water depth, and is subsequently retracted again correspondingly when returning.

The sensor is arranged, in particular, on the hydrofoil apparatus or the receptacle or the float. The sensor preferably has at least one ultrasonic transducer. As a result, spacings or distances can be determined particularly reliably under water.

As an alternative or in addition to a depth sensor, by way of which the immersion depth of the water sports device is detected, one development according to the invention of the water sports device comprises a movement state sensor for determining the spacing of the float from the water surface. The depth and movement state sensor can also be configured by way of a single sensor or a single sensor arrangement. Valuable information for stabilization of the movement is obtained from the detection of the spacing of the float, which information is processed by the control unit for stabilization of the movement and can be incorporated, for example, into control commands for thrust vector control.

In particular, the movement state sensor is a sensor unit which is preferably integrated into a link of the holding apparatus or is arranged on it or them. For example, it can be a sensor strip which operates on a capacitive basis and extends along a link of the holding apparatus or is integrated into the latter over the link length. It can likewise be a sensor unit with a plurality of, in particular, capacitive sensors, which sensor unit is arranged spaced apart from one another along the holding apparatus, for example in or on the links thereof. As an alternative or in addition, the spacing can be determined by an ultrasonic sensor unit. The sensor data can be used to extrapolate the spacing of the float from the water surface by means of the control unit in the case of a known position of the holding apparatus or its links and, in particular in combination with further sensor data, for example in respect of the movement speed and/or the depth of the water, a desired stable movement state can be aimed for, for example by raising or lowering of the float by means of a setting of one or more hydrofoils or by way of actuation of the holding apparatus or by way of a change in the movement speed. It goes without saying that a movement state sensor of this type which, as a single sensor or a sensor unit comprising a plurality of sensors, is arranged in or on the holding apparatus can also be used in the case of holding apparatuses which are arranged rigidly on the float and in the case of which the holding apparatus holds the hydrofoil apparatus in the same position with respect to the float both in the operating position and in the rest and/or starting position.

In particular, the movement state sensor is laminated in, that link of the holding apparatus which has the sensor preferably being produced from a fiber composite material, with the result that firstly a stable construction of the link is achieved and secondly at the same time the integration of the movement state sensor is simplified. Tailored sensor structures can be applied directly to the nonwoven or woven fabric to be used by way of printing processes such as screen printing, dispensing or inkjet printing, the movement state sensor becoming an integral constituent part of the structure of the holding apparatus as a result of the integration of the printed non-woven or woven fabric into the layer structure and subsequent fiber composite production, for example by way of vacuum infusion.

A water sports device, in particular in the form of a hydrofoil board, which is equipped with a movement state sensor preferably has a visual display unit which, in particular, extends at least over half of the length of the upper side of the float and which is configured, in particular, for displaying the spacing of the float from the water surface, for which purpose the display unit has one or preferably a plurality of lights. The spacing from the water surface can preferably correlate, for example, with the number and/or arrangement of the illuminated dots of the display unit. In particular, RGB diodes can be used for this purpose. For example, in the case of the float lying on the water, no lights or only a few lights which are, for example, red light up and the greater the spacing becomes, the more the number and/or color of the lights over the float link change until a certain, for example maximum, number of illuminated dots are activated in the case of a desired state. For example, a certain, desired or optimum spacing from the water surface can be identified by way of predominantly or exclusively green lights in the form of, for example, RGB LEDs or LED units. As an alternative or in addition, an indicator for a stable state, that is to say the stability of the movement, can be configured by means of the display unit in the float. A stable state is, in particular, a state, in which light weight shifts or foot movements of less than 15 cm on a water sports device which is configured as a hydrofoil board do not yet lead to a fall of the person riding it as a result of overturning and dipping of the float, previously arranged spaced apart from the water surface, into the water.

The energy store which has, in particular, a spring can preferably be prestressed by means of a drive motor. In particular, the spring is configured as a torsion spring, the torsion axis of which coincides with the rotational axis of the shaft which is coupled mechanically to the motor. In the case of this construction, the motor serves for prestressing or torsion of the energy store, and generates potential energy therein as a result. The potential energy can be called up for at least partial transfer of the hydrofoil apparatus, without it being necessary for energy generated by the motor to be used directly for this purpose.

The drive has, in particular, a transmission gear mechanism, via which the motor is connected to the energy store. The gear mechanism is configured, in particular, in such a way that the quotient from the time required for the transfer and the time required for the associated prestressing is <1. This means that the drive is configured in such a way that less time is required for the output from the energy store of the energy quantity required for the transfer than for the build-up of the same energy quantity by way of the motor. As a result, the above-described functions can be brought about by way of a motor with a comparatively low rated power output and therefore a relatively small overall size, since the interval between two transfer operations is generally speaking even sufficient for a prestressing time which is therefore long.

The energy store has at least one spring which is connected directly or at least coupled mechanically to at least one link of the holding apparatus, in such a way that the force of the spring can be used at least partially for positioning, in particular for orienting of the link. The energy store can preferably be prestressed in opposite directions by way of the motor and/or the gear mechanism. As a result, both a transfer of the hydrofoil apparatus into the operating position and a return from the operating position are at least facilitated by way of the drive. The drive preferably has a brake apparatus which brakes the transfer or the energy output of the energy store and therefore reduces the risk of injury and excessively abrupt influences on the movement of the water sports device.

The propulsion apparatus preferably has at least one propeller or impeller which is shaftless and/or hubless, the impeller being arranged at least partially, in particular, in a flow duct of a propulsion body, which flow duct is connected via at least two openings to the surroundings. The propulsion apparatus is particularly suitable as a result for being operated close to the bank or the beach, since firstly the risk of injury is reduced considerably by way of the arrangement in a flow duct, and secondly any growth of algae or the like here is considerably less in the flow duct and, in particular, on the impeller.

In particular, the motor has a hollow rotor which forms part of the flow duct by way of its inner side, is mounted outside the flow duct, in particular, on its outer side which is directed away from the flow duct, and supports blades, and an outer stator which is arranged in a propulsion body housing. Essential functional parts of the motor are therefore arranged around the cooling duct, with the result that, in contrast to a propeller which is provided with a hub or shaft, the excess heat which is produced can be dissipated over a greater surface area into the flow duct and, in the case of a propulsion body housing which is, in particular, cylindrical or torpedo-shaped, can also at the same time be dissipated in an improved manner to the outside. In one embodiment according to the invention with a propulsion apparatus which has an electric motor which is configured, in particular, as an internal rotor motor, this can therefore be of particularly satisfactorily streamlined configuration. In the case of a propulsion apparatus with an internal combustion engine, in contrast, a particularly high degree of efficiency with a simultaneously great power output is achieved.

The impeller is particularly preferably formed by way of individual blades which are not connected directly to one another and are mounted rotatably. As a result, the angles of attack of the blades of the impeller can be changed during operation and can be adapted to the speed of the water sports device. As a result, the acceleration and/or the maximum speed which can be achieved can be increased in comparison with the use of an impeller with a constant angle of attack, in the case of an identical motor power output.

The propulsion apparatus and therefore the water sports device can preferably be operated both in the rest and/or starting position and in the operating position with the result that various ability levels of any users can be taken into consideration. In addition, in this case, the propulsion apparatus can also be utilized in the rest and/or starting position, for example, in shallow regions which are close to the bank.

The water sports device preferably comprises a propulsion apparatus which is provided for the propulsion thereof and the propulsion motor of which, which is arranged on the float side, is drive connected to a propulsion element via a propulsion train which can be moved in an angular manner. As a result, the hydrofoil apparatus can be of more streamlined design. A motor which is arranged in the float is subject to less strict installation space restrictions, and can therefore be, for example, of more maintenance-friendly configuration.

The water sports device and, in particular the propulsion apparatus, preferably have at least one sensor arrangement which can be used for positional determination, the control unit of the water sports device being configured, for the purpose of geo-fencing, for generating control signals on the basis of signals of the sensor arrangement.

One or more controllable elements of the water sports device is/are actuated by means of the control signals. These can include, in particular, a motorized drive of the propulsion apparatus, movable means for producing an orientation of a water jet (for example, a vane, motor, rudder blade, a fin and/or nozzle), and/or retractable and extendable elements (a centerboard, a holding apparatus and/or hydrofoil apparatus) which influence the floating properties of the water sports device.

In the present case, geo-fencing is understood to be the automatic generating and triggering of control signals when a predefined region of the body of water which is being crossed is departed from or when a predefined and then, in particular, restricted region of the body of water which is being crossed is reached.

The sensor arrangement has sensors which are known for the respective purpose. In accordance with one development of the invention, for example, positional determination according to the invention comprising the spacing above the bottom takes place, in particular, by means of sound-based methods and associated transmitting and receiving sensors, the signals of which are evaluated by the control unit.

For the control of the water sports device and, in particular, the propulsion apparatus, the control unit comprises customary means such as a man/machine interface, electric and/or electronic data processing means and interfaces to any functional systems which are present such as sensors. Moreover, the control unit preferably has an interface to a communications unit, or the latter is integrated directly into the control unit. The control unit is preferably arranged in a housing, but can also be arranged distributed in various regions of the water sports device. A bus system is preferably used for the communication of individual components of the water sports device.

In particular, the positional determination comprises the determination of the geographical position, in particular comprising the longitudinal and latitude. Against the backdrop of available positional sensors which are used, for example, for the detection of signals of a GPS, Glonass or Beidou system, control signals such as, for example, a reduction in the motor power output of a propulsion apparatus can be generated in an automated manner when a predefined region is left.

The sensor arrangement and/or the control unit are/is preferably configured for determining the spacing from a use location, with the result that corresponding control signals are generated, for example, when a maximum spacing is reached. The determination of the spacing from a use location can take place purely locally on the part of the water sports device, for example via the positional determination and the definition of the use location, but it can also take place via bidirectional communications with communications means which are present on the part of the water sports device and on the part of the use location, with the result that the spacing can be determined, for example, via propagation times of the communications signals or their signal strength.

In accordance with a further embodiment of the invention, there is an external controller which is configured for transmitting control signals, generated on the basis of the position of the water sports device, to the control unit. A computer-based controller of this type comprises necessary communications means on the part of the water sports device and the external controller which is situated, for example, on the bank. The controller can also be present, for example, on a ship, from which the water sports device starts. The no-go zone can preferably be generated dynamically on the basis of the position of the ship, for example as a circle situated around the ship along the water surface with a diameter of 300 m.

The control unit is advantageously configured for communication with a control unit of a further propulsion apparatus thereof or of a further water sports device. This results in a multiplicity of possible interactions between the two water sports devices and/or the users. For example, a teacher/student mode or attend a mode for synchronized movements can be realized. Pursuit modes can likewise be implemented, reaching a minimum, in particular predefined, spacing being evaluated as a success, for example, and the movement of the water sports devices being decelerated. The speeds of the two or more water sports devices can also be matched to one another or can be predefined in regions. Here, in particular, the control unit is configured for generating control signals for one or the two propulsion apparatuses on the basis of the positional, control and/or movement signals/data transmitted from the further water sports device.

The possible uses of a water sports device according to the invention are extended if, in accordance with a further development according to the invention, the water sports device has two propulsion apparatuses, there being a passenger area between the two propulsion devices in a plan view. The passenger area is understood to mean that area which is present for accommodating people during the operation of the water sports device, and in which one or more people can, for example, stand, kneel, lie and/or sit. As a result of the arrangement according to the invention of the propulsion apparatuses,

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

FIG. 1 shows an object according to the invention in a side view.

FIG. 2 shows the object according to FIG. 1 in a view from the rear.

FIGS. 3 a to 3 c show a propulsion apparatus of an object according to the invention.

FIGS. 4 a to 4 c show an alternative propulsion apparatus of an object according to the invention.

FIGS. 5 a to 5 c show a further alternative propulsion apparatus of an object according to the invention.

FIG. 6 shows two objects according to the invention in a further use situation.

FIGS. 7 a to 7 c show a further object according to the invention in a perspective view.

FIGS. 8 a to 8 b show a further object according to the invention in a perspective view.

FIG. 9 shows the object according to FIG. 1 in a use situation.

FIGS. 10 a to 10 c to show a part of one exemplary embodiment according to the invention.

FIGS. 11 and 12 show a further exemplary embodiment according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Individual technical features of the exemplary embodiments which are described in the following text can also lead in combination with the features of the independent claim to developments according to the invention. If appropriate, functionally identical parts are provided with identical designations.

The water sports device 2 according to the invention is configured for self-stabilization. This takes place via a control unit 70 which is provided to this end. The latter generates control signals for actuating means. Said actuating means can be pivotably arranged hydrofoils 16 of the hydrofoil apparatus 6 (FIG. 7 ) or pivotably arranged sections of the hydrofoils 16 (FIG. 8 ).

As an alternative or in addition, a vector nozzle 92 (FIG. 1 , FIG. 4 ), a pivotably arranged propeller 64, pivotable guide vanes 94 (FIG. 3 ) which are preferably arranged at an outlet opening 60 of the propulsion apparatus 50, and/or nozzles 66 which can be arranged both in a stationary or pivotable manner (FIG. 5 ) can be provided.

By way of the adjustment of the hydrofoils 16 and/or the apparatuses of a vector control which are arranged on the propulsion apparatus 50, the water sports device or system consisting of the water sports device and its user can be loaded with forces which repeatedly move it in the direction of the stable position.

The exemplary embodiment (shown in FIG. 1 ) of the water sports device 2 according to the invention comprises a float 4 which is connected via a hydrofoil apparatus 6 to a holding apparatus 8. The holding apparatus 8 comprises two links 10 which are arranged at one end in an articulated manner on the float 4 and at the other end in an articulated manner on the hydrofoil apparatus 8. Via an internal drive 12 which is shown using dashed lines, the front links 10 which are arranged on a common shaft are moved in the movement direction F. Via the coupling, the rear (in the movement direction F) links 10 are positively guided by means of the propulsion apparatus 50 of the hydrofoil apparatus 6. In this regard, merely a single drive 12 of sufficient dimensions is necessary.

In the present case, the propulsion apparatus 50 is configured with a hubless impeller 52 (FIG. 2 ). The associated motor has a rotor which forms part of the flow duct by way of its inner side and is correspondingly hollow, the blades 54 being fastened on the inner side of the rotor. The rotor is mounted outside the flow duct on its outer side which is directed away from the flow duct, and runs in a stator which is arranged in a propulsion body housing 56.

A vector nozzle 92 is arranged at the outlet 60 of the propulsion apparatus 50. A control unit 70 generates control commands for the vector nozzle 92, by way of which the thrust vector of the propulsion apparatus 50 can be changed. Via this, self-stabilization of the water sports device or of a system comprising the water sports device and its user can be achieved. To this end, the control unit 70 can evaluate signals of the sensor arrangement 74.

The links 10 are of optimized-flow configuration with a smaller extent as viewed in the movement direction F and transversely with respect thereto (FIGS. 1 and 2 ). Moreover, the incident flow faces are rounded, and the links are of teardrop-like or wing-like configuration in cross section, in particular.

Two laterally projecting housing walls 58 (cf. FIG. 1 ) delimit two openings which are configured as inlet openings and are situated on the surfaces which face away from one another, through which openings the water which is accelerated and ultimately ejected through the outlet opening 60 passes beforehand into the internal flow duct. The propulsion apparatus comprises the propulsion body housing 56 which is fixed in two receptacles 62 and has an internal propulsion energy store, the motor which is configured as an internal rotor motor including a hubless impeller, and a control unit 70 which is configured with a man/machine interface for operating the propulsion apparatus. Corresponding line means lead, for example, through the links 10 into the float 4, and are transmitted from there, for example, wirelessly to a hand-held unit 90 of the user 86 operating the water sports device 2 (FIG. 6 ).

Via a handheld unit of this type, for example, the transfer of the hydrofoil apparatus 6 with its hydrofoils 16 out of the operating position which is shown into a starting and/or rest position of the hydrofoil apparatus 6 closer to the float 4 can be enabled or triggered.

According to the invention, the transfer can be brought about, for example, by way of control signals of a control unit 70 which is arranged in the float 4 and is therefore shown merely using dashed lines, in an automatic manner on account of the evaluation of said control signals within the context of geo-fencing (FIG. 1 ). For this purpose, the control unit 70 receives signals of the sensor arrangement 74 via a signal line 72 which is shown using dotted lines. Control signals are generated on the basis of said signals if an internally or externally predefined area, in which the water sports device 2 may be used, is left. A control signal is generated automatically in the control unit 70 only when a predefined boundary 83 of a use area 82 of the water sports device 2 is left (cf. FIG. 9 ). Said control signal can lie, for example, at the transition of the hydrofoil apparatus 6 into the rest and/or starting position of the hydrofoil apparatus 6 and, for example, at throttling of the drive power output of the propulsion apparatus 50. For this purpose, the sensor arrangement is configured, for example, for receiving GPS signals or other localization signals and/or the spacing above the bottom by means of an acoustic signal. For the latter, the lower side of the float 4 has corresponding transmitting and receiving units 76. They are likewise coupled again to the control unit 70 via a corresponding signal line 72.

The foil board which is shown in FIGS. 1 and 2 can then be transferred back to its use location in a manner which is controlled via weight shifting. As an alternative or in addition, the foil board can also be configured for determining the spacing from a use location 78, in accordance with FIG. 9 . For this purpose, for example, the transmission duration of a time-coded signal between a central controller 80 which is assigned to the use location 78 and the water sports device 2 is determined. Via a controller 80 of this type, further control options can also be carried out by a user having corresponding access permissions, in particular if the water sports device leaves a use area 82 via its boundary 83.

The sensor arrangement 74 can also be supplemented by a communications unit, by which the control units 70 of two water sports devices 2 which are correspondingly in a synchronous mode with one another can communicate with one another, indicated by way of the signals 84 which are shown using a plurality of curved lines. In a mode of this type, for example, a person 86 authorized as instructor can give movement signals to a learning person 88 by means of the handheld unit 90 which is attached wirelessly to the control unit 70, which movement signals lead, for example, to the initiation of cornering as a result of folding away of the movable hydrofoils 16 of the hydrofoil apparatus 6. Moreover, the area of use of the water sports devices 2 is restricted to an area 82 defined by way of geo-fencing by way of the correspondingly programmable control unit 70 (not shown in the present case) (cf. FIG. 9 ).

FIG. 3 shows a propulsion apparatus 50 of a water sports device 2 according to the invention in one embodiment. The propulsion apparatus 50 has an impeller 52. Guide vanes 94 are arranged at the end of the propulsion apparatus 50. Here, the guide vanes 94 form a cross, the arms of which are arranged turned by 90° with respect to one another. The guide vanes 94 can be pivoted about pivot axes, two guide vanes being arranged on each pivot axis. The guide vanes can be pivoted around the pivot axis, the horizontally arranged guide planes 94 can be pivoted from left to right and vice versa, and the horizontally arranged guide vanes 94 can be pivoted from top to bottom and vice versa. FIG. 3 a shows the guide vanes 94 in the neutral position. In FIG. 3 b , the vertically arranged guide vanes 94 are pivoted to the right and the horizontally arranged guide vanes 94 are pivoted to the bottom, and, in FIG. 3 , the horizontally arranged guide vanes are pivoted to the top. It is possibly also conceivable for each of the four guide vanes 94 to be designed so as to be individually pivotable. As a result, for example, a torque about a longitudinal axis of the propulsion apparatus 50 can be generated.

FIG. 4 shows an alternative refinement of a corresponding propulsion apparatus 50 with an impeller 52, which propulsion apparatus 50 is equipped with a vector nozzle 92. Via the vector nozzle 92, the drive jet of the propulsion apparatus 50, the rearwardly ejected water quantity, can be oriented. FIG. 4 a shows the vector nozzle 92 in the neutral position. FIG. 4 b shows the vector nozzle 92 pivoted to the left, and FIG. 4 c shows it pivoted to the bottom. By way of corresponding orientation of the vector nozzle 92, a directed force can be exerted on the propulsion apparatus 50 and therefore on the water sports device 2.

FIG. 5 shows a further alternative refinement of the propulsion apparatus 50 with a plurality of nozzles 96. Said nozzles 96 can either be configured as vector nozzles 92 and therefore have a variable position. As an alternative, the propulsion apparatus can also have a plurality of nozzles 96 which are oriented in different directions in a fixed manner. Control of the water sports device can be achieved by virtue of the fact that the drive jet which is ejected through defined nozzles 96 is regulated, for example, by way of valves. The drive jet is then ejected, for example, only through defined nozzles 96, or the proportion of the drive jet which exits through defined nozzles 96 is correspondingly variable.

FIG. 5 a shows a propulsion apparatus 50 with five nozzles 96 as vector nozzles 92. FIG. 5 b shows said nozzles 96 in a position, in which they are pivoted toward the bottom left. FIG. 5 c shows nozzles 96 which point in different directions. These can either be vector nozzles 92 which are actuated independently of one another, or nozzles 96 which are not variable and in the case of which merely the proportion of the drive jet which exits through the respective nozzle can be varied.

FIG. 6 shows two water sports devices, in the case of which self-stabilization can take place as an alternative or in addition by way of the hydrofoil apparatus 6 with pivotably movably arranged hydrofoils 16. Via the control unit 70, signals for adjusting the adjustable hydrofoils 16 can therefore be transmitted, and the hydrofoils 16 can be adjusted.

FIG. 7 and FIG. 8 show two water sports devices 2 with alternative refinements of the hydrofoil apparatus 6 or the hydrofoils 16. The hydrofoil apparatus 6 is arranged on the propulsion apparatus 50. In the variant according to FIG. 7 , the individual hydrofoils are arranged pivotably directly on the propulsion apparatus 7. FIG. 7 a shows the hydrofoils 16 in the neutral position. In FIG. 7 b , the hydrofoils 16 are pivoted downward and at the same time the right-hand (in the movement direction of the water sports device 2) hydrofoils 16 are pivoted against the propulsion apparatus. FIG. 7 c shows the hydrofoils in a transport position or rest position. The control unit 70 of the water sports device 2 can actuate the individual hydrofoils 16 in such a way that automatic self-stabilization of the water sports device 2 in the water takes place.

FIG. 8 shows an alternative refinement of the hydrofoil apparatus 6. Here, a front and a rear hydrofoil which at least partially configure the hydrofoils are arranged on the propulsion apparatus 50. Pivotable tips of the hydrofoils 16 are arranged on said rigid hydrofoils in each case at the ends, which pivotable tips can be pivoted into various positions. As a result, stabilization of the water sports device 2 can also be achieved by way of adjustment of the hydrofoils 16, merely the pivotably arranged tips of the hydrofoils 16 in FIG. 8 .

FIGS. 10 a to c show one advantageous embodiment of an impeller 52, in the case of which blades 54 can be rotated and can therefore have their angle of attack adjusted. Here, the individual blades 54 are connected to one another merely indirectly. To this end, the propulsion apparatus 50 has a motor 200 which is configured as an internal rotor motor with a stator 202 and a rotor 204. On its outer side which is directed away from the flow duct, the rotor 204 is mounted by way of two radial bearings 206 which are configured in the present case as magnetic bearings and an axial bearing 208 which is likewise configured in the present case is a magnetic bearing. An impeller ring 210 which has pivotable blade receptacles 211 is arranged on the rotor. In each case one blade 54 is arranged on the blade receptacles 211. The propulsion apparatus 50 has an adjustment ring 212 which is arranged coaxially with respect to the rotor 204 or the impeller ring 210. The adjustment ring 212 is likewise hollow and is mounted on its outer side which is directed away from the flow duct. The spacing between the adjustment ring 212 in the impeller ring 210 is variable here in the axial direction. In the present case, this is achieved by way of active magnetic axial positioning in a magnetic bearing 214 of the adjustment ring 212. The adjustment ring 212 is in engagement via individual adjustment pins 216 with cylindrical outer sections of the blade receptacles 211. If the axial spacing between the adjustment ring 212 and the impeller ring 210 is changed by the magnetic bearing 214, this translational movement is converted by way of the interaction of the adjustment pins 216 and the blade receptacles 211 into a rotational movement of the blades 54, via which rotational movement the blades 54 can be pivoted. As a result, the angle of attack of the blades 54 can be set.

In accordance with a further exemplary embodiment according to the invention, a plurality of capacitive sensors 36 for configuring a movement state sensor 32 are arranged along a link 10 of the holding apparatus 8 (FIGS. 11 and 12 ). They extend uniformly over a large part of the link 10 along its longitudinal extent and transmit corresponding data to a control unit which is preferably arranged on the float 4, in a manner which is dependent on whether they are arranged above or below a water surface 34 which is indicated in each case by way of dashed lines. As a result, a spacing of the float 4 from the water surface 34 can be determined in said control unit, whereupon, in the case of undesired states, the control unit can adapt, for example, the thrust of the propulsion apparatus 50 which is integrated into the link 10 or an angular position of a hydrofoil 16, in order, in addition to the thrust vector control, to achieve a more stable movement state and to stabilize the water sports device.

The exemplary embodiment of FIGS. 11 and 12 has, furthermore, a visual display unit 31 which is integrated into the float and shows the spacing of the float 4 from the water surface. The display unit 31 comprises a plurality of multicolor LED units 33 which are laminated in, with the result that the spacing from the water surface 34 can be shown via the number and/or wavelength of the illuminating LED units 33. 

1. A water sports device comprising: a float; a hydrofoil apparatus which is fastened by a holding apparatus to the float, and a propulsion apparatus which is provided for the propulsion of the water sports device, wherein the hydrofoil apparatus is arranged on a link of the holding apparatus having one or more hydrofoils, wherein the float transferring into a position which is spaced apart from the water surface in the operating position and during a forward movement on account of a buoyancy brought about by way of the hydrofoil apparatus; wherein the propulsion apparatus is configured for automatic self-stabilization of the water sports device, and the water sports device has a control unit which is provided to this end.
 2. The water sports device as claimed in claim 1, wherein the propulsion apparatus is configured for thrust control.
 3. The water sports device as claimed in claim 31, wherein the control unit is configured for self-stabilization of the water sports device by means of the thrust vector control.
 4. The water sports device of claim 1, wherein the propulsion apparatus has a vector nozzle.
 5. The water sports device of claim 1, wherein the control unit is configured for multiple-axis stabilization of the float.
 6. The water sports device of claim 1, wherein the propulsion apparatus has a pivotable propeller.
 7. The water sports device of claim 1, wherein the propulsion apparatus has at least one pivotable guide vane.
 8. The water sports device of claim 1, wherein the propulsion apparatus has a plurality of nozzles which point in different directions.
 9. The water sports device of claim 1, further including at least one sensor from a group comprising gyro sensors, speed sensors, position sensors (GPS, Glonass, Beidou, etc.), distance sensors (echo sounders, sonar), infrared sensors and inclinometers.
 10. The water sports device as claimed in claim 9, wherein the control unit is configured for processing the signals of the one or more sensors and for forming control signals on the basis of said signals.
 11. The water sports device of claim 1, wherein a plurality of selectable movement profiles are stored in the control unit.
 12. The water sports device of claim 1, wherein the control unit is configured for setting different spacings from the water surface in the operating position.
 13. The water sports device of claim 1, wherein the hydrofoil apparatus is configured for setting different angles of attack of at least parts of the one or more hydrofoils and/or of rudders of the hydrofoil apparatus.
 14. The water sports device of claim 1, wherein the control unit is configured for speed-dependent setting of the hydrofoil apparatus and/or the holding apparatus.
 15. The water sports device of claim 1, wherein the control unit is assigned at least one handheld unit.
 16. The water sports device of claim 1, further including a dead man's apparatus.
 17. The water sports device of claim 1, wherein the hydrofoil apparatus can be transferred, via the holding apparatus out of the rest and/or starting position into an operating position below the float.
 18. The water sports device of claim 17 wherein the holding apparatus has a drive which is provided with an energy store, via which the hydrofoil apparatus can be transferred out of the rest and/or starting position into the operating position and/or out of the operating position into the rest and/or starting position.
 19. The water sports device of claim 1, wherein the holding apparatus has a further link which is mounted pivotably at one end on or in the float and is arranged pivotably at the other end on the hydrofoil apparatus.
 20. The water sports device as claimed claim 18, further including a control apparatus which is configured for controlling the drive, and at least one depth and/or proximity sensor which is connected to the control apparatus, the control apparatus being configured to change the spacing of the hydrofoil apparatus from the float in a manner which is dependent on the spacing of the water sports device from the bottom and/or an obstacle.
 21. The water sports device as claimed in claim 18, wherein the energy store has at least one spring which is prestressed by means of a drive motor.
 22. The water sports device of claim 1, wherein the propulsion apparatus is configured at least partially as part of the hydrofoil apparatus.
 23. The water sports device of claim 1, wherein the propulsion apparatus comprises an electric motor or an internal combustion engine.
 24. The water sports device of claim 17, wherein the propulsion apparatus is operable both in the rest and/or starting position and in the operating position.
 25. The water sports device of claim 1, further including a motor of the propulsion apparatus, which motor is arranged on the float side and is drive-connected to a propulsion element via a propulsion train which can be moved in an angular and/or longitudinal manner.
 26. The water sports device of claim 1, wherein the propulsion apparatus has a sensor arrangement which can be used for positional determination, and the control unit is configured, for the purpose of geo-fencing, for generating control signals on the basis of signals of the sensor arrangement.
 27. The water sports device of claim 1, further including at least one movement state sensor for determining the spacing of the float and/or the hydrofoil apparatus from the water surface.
 28. The water sports device of claim 1, further including a visual display unit.
 29. The water sports device as claimed claim 19, further including a control apparatus which is configured for controlling the drive, and at least one depth and/or proximity sensor which is connected to the control apparatus, the control apparatus being configured to change the spacing of the hydrofoil apparatus from the float in a manner which is dependent on the spacing of the water sports device from the bottom and/or an obstacle.
 30. The water sports device as claimed in claim 2, wherein the propulsion apparatus is configured for automatic thrust control.
 31. The water sports device as claimed in claim 2, wherein the propulsion apparatus is configured for automatic thrust vector control.
 32. The water sports device as claimed in claim 9, wherein the propulsion apparatus includes the at least one sensor. 